The present invention relates to oil separators and more particularly to an oil separator for use in a refrigeration system to separate oil from an oil/refrigerant gas mixture.
Refrigeration systems utilize a compressor to compress a refrigerant gas, a condenser to cool the compressed gas and to cause the gas to condense to a liquid and an evaporator for absorbing heat from the area to be refrigerated as the liquid refrigerant expands and evaporates. In many such systems, oil is used as a lubricant and to provide a more effective seal in the compressor and, by such use, is mixed with the refrigerant gas in the compressor and is carried along with the refrigerant. Oil, however, is not a refrigerant and therefore it reduces the efficiency of the system if the oil is permitted to remain mixed with the refrigerant gas as it moves to the condenser. Therefore, it is known to provide an oil separator in the line between the compressor and condenser to remove the oil from the refrigerant gas. Generally, refrigerant gas from the compressor contains oil in the form of a fog as it enters the oil separator inlet.
Various arrangements have been provided for separating the oil from the gas. For example, U.S. Pat. No. 3,778,984 discloses an arrangement for introducing the oil and gas mixture tangentially to a separator so as to centrifuge the oil from the gas so that the oil will fall downwardly under the force of gravity into a collecting chamber in the bottom of the separator. U.S. Pat. No. 4,478,050 discloses an oil separator in which fluid is introduced tangentially in a chamber bounded by a screen upon which the oil particles collect. The oil and refrigerant mixture is caused to flow in a vortex providing centrifugal separation of oil particles. Deflector tabs are provided to enhance or regenerate the vortex in the lower portion of the chamber above the oil outlet opening. U.S. Pat. No. 4,263,029 discloses an oil separator in which fluid is introduced tangentially in a passageway formed by a spiral wall having a single revolution. The fluid then passes to a chamber bounded by an annular ring and then to a chamber bounded by a funnel shaped wall with a central opening for passage therethrough of collected oil and including vanes for guiding the oil to the opening. The "oil free" gas leaves the separator through a central, axial passage.